// Copyright (c) 2024 PaddlePaddle Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <stdio.h>
#include <string.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/types.h>

#include "paddle/extension.h"

#define SPECULATE_MAX_BSZ 256
#define MAX_DRAFT_TOKENS 6

struct msgdata {
  int64_t mtype;
  int mtext[SPECULATE_MAX_BSZ * MAX_DRAFT_TOKENS + SPECULATE_MAX_BSZ +
            2];  // stop_flag, bsz, accept_num*bsz, tokens...
};

void SpeculateGetOutput(const paddle::Tensor& x,
                        int64_t rank_id,
                        bool wait_flag) {
  if (rank_id > 0) {
    return;
  }
  static struct msgdata msg_rcv;

  static key_t key = ftok("./", 1);

  static int msgid = msgget(key, IPC_CREAT | 0666);

  int64_t* out_data = const_cast<int64_t*>(x.data<int64_t>());
  int ret = -1;
  if (!wait_flag) {
    ret = msgrcv(
        msgid,
        &msg_rcv,
        (SPECULATE_MAX_BSZ * MAX_DRAFT_TOKENS + SPECULATE_MAX_BSZ + 2) * 4,
        0,
        IPC_NOWAIT);
  } else {
    ret = msgrcv(
        msgid,
        &msg_rcv,
        (SPECULATE_MAX_BSZ * MAX_DRAFT_TOKENS + SPECULATE_MAX_BSZ + 2) * 4,
        0,
        0);
  }
  if (ret == -1) {
    out_data[0] = -2;
    out_data[1] = 0;
    return;
  }
  int bsz = msg_rcv.mtext[1];

  for (int64_t i = 0;
       i < SPECULATE_MAX_BSZ * MAX_DRAFT_TOKENS + SPECULATE_MAX_BSZ + 2;
       i++) {
    out_data[i] = (int64_t)msg_rcv.mtext[i];
  }
  return;
}

PD_BUILD_OP(speculate_get_output)
    .Inputs({"x"})
    .Attrs({"rank_id: int64_t", "wait_flag: bool"})
    .Outputs({"x_out"})
    .SetInplaceMap({{"x", "x_out"}})
    .SetKernelFn(PD_KERNEL(SpeculateGetOutput));
